Rheostat.



PATENTED JULY 28, 1908.

G. H. DORGBLOH RHEOSTAT.

APPLICATION FILED JAN. 11. 1903.

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UNITED STATEtLIjfIENT OFFICE.

GEORGE 11.1)ORGELOH, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIO COMPANY, A CORPORATION OF NEW YORK.

RHEOSTAT.

Specification of Letters Patent.

Patented July 28, 1908.

' Application filed January 11, 1908. Serial No. 410,322.

To all whom it may concern."

Be it known that I, GEORGE H. DoRoELoH,v

' ing resistances a pair of controlling arms, one

for each resistance. These arms are arranged so as to operate independently of each other to vary the resistances. The arms are preferably concentrically pivoted and the construction and arrangement is such that the field control arm is mechanically locked against movement until the starting arm is move/d to running or short-circuited position. The arms are so interlocked that upon failure of voltage the starting arm will return to the off position and carry wlth it the field control a/I'hl.

1n the accompanying drawing in which I have shown my invention embodied in concrete/mechanism, Figure 1 is a plan view of the device showing the circuit connections and Fig. 2 is a side elevation of the controlling mechanism.

. ltcferring to the drawing, 10. is an insulat- )ng base of slate or soapstone provided with a I series of studs 11 forming the terminals of handle 19. stud 20 and is moved independently ofthe starting resistance 12 and a series of studs 13 similarly connected to a speed controlling resistance 14. The vstuds ll and 13 are preferably concentrically arranged as shown and are adapted to be engaged by.the controlling arms 15 and 16 respectively. The controlling arm- 15 which engages the studs 11' is biased to the off position by means of a spring 17 and is arrangedto be held in running position in the usual way by means of the novoltage magnet 18. This arm 15 is operated independently of the arm 16 by means of the The arm 16 is pivoted upon the arm 15 to engage the studs 14 by means of the handle 21. The hub 22 of this arm is cut away to form a notch 23, which is adapted to be engaged by a latch or pawl 24 to lock the same in the starting-position shown in Fig. 1. This latch is spring-pressed into the notch and is provided with a pin 25 which projects upwardly in the path of the arm 15. When this latter arm engages the pin 25, it.forces the pawl out of the notch 23 and releases the arm 16.

The arrangement of circuits and the mode of operation are as follows:' The resistance I 14 is preferably connected in the field circuit of the motor while the starting resistance 12 is in the armature cir'cuit'in the usual way. To start the motor the line switch 26 being closed, the arm 15 is first moved to the right to cut out starting resistance 12, current passing from the positive main to the arm 15,

resistance 12, armature A'and' back to line When the arm reaches short-circuiting or runningosition, it engages the pin 25 and releases t e arm 16. It is then held in running position by the no-voltage magnet 18'. The arm 16 is now free to be moved to insert resistance 14 in the circuit of the field F of the motor to increase its speed. The arm 16 may be left upon any of the studs 14 as desired. Upon failure of voltage the arm 15 will return to the starting position and carry, with it the arm 16 so that the motor will always be started at maximum field strength. While I have described my invention as embodying certainstructural features and circuit arrangement, it should be understood that I do notlimit m invention in these particulars except in so ar as it is limitedby the see c of the claims annexed hereto.

hat I claim as new and desire to secure by Letters Patent of the United States, is

1. A motor starting and speed regulating I rheostat'comprising an armature resistance and a field resistance, pivoted controlling members arranged to move independently of each other to vary said resistances, and means for preventing movement of the field. control member unt1l the armature control member reaches short-circui'ted position.

2. A motor starting and speed regulating rheostat comprising a field resistance and a controlling arm therefor, a starting resistance having a controlling arm biased to off position'and movable independently of said field arm to vary its resistance, and means for preventing movement of the'field arm untll the starting arm reaches running osition.

3. A motor-starting and spee regulatin rheostat comprising a starting resistance an a speedregulating resistance, concen; cally independently of each other 'to vary said resistances, and means for preventing movement of the speed regulating arm until the starting arm reaches running position.- 4. A motor starting and speed regulating rheostat com rising a starting resistance and aspeed re'tu ating resistance, concentrically ivoted controlling arms arranged to move independently of each other over the same path to vary said resistances, and means hor preventing movement of the speed regulating member until the starting arm reaches running position. 4 1 5. A motor startingand speed regulating rheostat com rising a startingresistance and a speed regu ating resistance, concentrically ivoted controlling arms arranged to move independently of each other to'vary said resistances, and means for mechanically looking the speed regulating arm against movement until the starting arm reaches running position? v a 6. A motorstarting and -speed regulating rheostat comprising a field resistance and a controlling. arm therefor, a starting resistance having the control arm biased to the 'off position ,and movable independently 'of ,said arm to vary its resistance, means for reventmg movement of the field arm until t e starting arm reaches running position, and means whereby the field arm is mbyed by the starting arm when the latter returns in r'esponse to its bias.

7. A motor starting and speed regulating rheostat com rising an armature resistance andia contro ing arm therefor, movable in one direction to cut out said resistance, a field-resistance and a controlling arm movable in the same direction and over the same 'path to insert said resistance, and means for preventing movement of .the field control arm untilthe starting arm reaches short-circuited position.

8. A motor starting and speed regulating rheostat, comprising'an armature resistance and a field resistance, concentrically pivoted controlling arms mounted for independent movement over the same ath to vary said resistances, connections whereby said arms are movable in opposite directions to insert resistance and means for mechanically lock- I ing one of said arms against movement until the other arm reaches a predetermined position. 9. A- motor control rhedstat, comprising anhrm'ature control mechanism providedwithno-voltage release features, and a field control mechanism movable independently of each other in opposite directions and over 4 the same'path to insert resistance, means for -interlocking the said mechanisms whereby the field control mechanism will be returned with the armature control mechanism upon failure of-volta e, and means for mechanically locking t e field control mechanism against movement until the armature control mechanism has reached running position.

In witness whereof, I have hereunto set my hand this 9th day of January, 1908.

GEORGE H. DORGELOH. Witnesses:

BENJAMIN 13.. HULL, HELEN ORFORD. 

